1. Field of the Invention
The present invention relates to a pixel control device and a display apparatus. More particularly, the present invention relates to a pixel control device and a display apparatus used in conjunction with the multi-domain vertical alignment (MVA) technology.
2. Descriptions of the Related Art
Limited by technologies and materials, early generations of liquid crystal display (LCD) screens provided relatively small viewing angles, low contrast qualities, and few pixels. Due to their relatively small sizes, earlier LCD screens were solely used in small portable devices, such as notebook computers, mobile phones, and personal digital assistants (PDA), where the viewing angle was not a key factor in determining the quality of the LCD screens. However, in recent years, as larger LCD screens were demanded in desktop computers and TV sets, the viewing angle became a key factor in determining the quality of the LCD screens.
Such a problem can be resolved by using multi-domain vertical alignment technologies (abbreviated as MVA hereinafter), which arrange the liquid crystals of the LCD screens in more than one direction, thereby, enlarging the range of viewing angles.
FIG. 1A depicts a schematic side view of a sub-pixel 1 in an LCD screen employing the prior MVA technologies. This sub-pixel 1 has a first electrode terminal 11, a second electrode terminal 12, a third electrode terminal 13, and a plurality of liquid crystals 14. When a first voltage level is applied to the first electrode terminal 11 and a second voltage level is applied to both the second electrode terminal 12 and the third electrode terminal 13 simultaneously, these liquid crystals 14 will be disposed at the same angle. In this sense, such MVA technologies support four domains. FIG. 1B depicts a schematic top view of the sub-pixel, wherein the regions circled by the dashed lines 151, 152, 153, 154 represent four domains.
However, LCD screens employing the four-domain MVA technologies wash out at large viewing angles. Washing out refers to the degradation of the perceived chrominance of the picture that the user views. As expected, these LCD screens are undesired by users.
In summary, it is important to manufacture LCD screens with wide viewing angles, while using MVA technologies and preventing washouts at large viewing angles.